The invention relates to a power source system of a portable information processing system using a battery, such as a personal computer which is driven by a battery power source and, more particularly, to a power source system of a portable information processing system using a battery which enables a long time operation by connecting and fixing an auxiliary battery unit to the system main body.
Since the use of a portable personal computer of the notebook type mainly in the outdoor is increasing, it is required that it can be used for a long time even in a state in which there is no AC adapter or the like.
Conventionally, as a battery unit of a portable type personal computer, a combination of a main battery unit built in the personal computer main body and an auxiliary battery unit is used. The auxiliary battery unit, which is attached to the outside, is a unit simply having a battery therein and accordingly, total battery capacity can be increased. In case of charging the auxiliary battery unit, the auxiliary battery unit which was completely used is detached from the computer main body and is set to an exclusive-use AC adapter, and is charged.
Therefore, when the conventional auxiliary battery unit is used, in a state where there is no AC adapter, there is a problem such that since the operation of a capacity larger than the capacity of a combination of the battery unit built in the personal computer main body and one auxiliary battery unit cannot be performed, it is difficult to perform the operation for a long time. Even if a plurality of auxiliary battery units are prepared, there is a problem such that it is troublesome to exchange the batteries during the operation.
When charging, it is necessary to charge each auxiliary battery unit. When a plurality of units are charged, there is a problem such that the exchange of the batteries for charging must be done many times.
Further, when the battery unit is connected, after the battery unit built in the computer main body is completely used, it is switched to the auxiliary battery unit attached to the outside. Due to this, even when the auxiliary battery unit is finished after that, the power supply to the computer is completely stopped. Therefore, even if a plurality of spare battery units are prepared, since it is impossible to continuously use the computer while exchanging the spare battery units, there is a problem such that the use of the computer must be temporarily stopped each time the spare battery unit is changed.